Series Polyunsaturated Fatty Acids Research Articles

Alteration of redox status and fatty acid profile in gills from the green crab (Carcinus aestuarii) following dimethoate exposure

Dimethoate is a broad-spectrum organophosphate insecticide and acaricide. Through various pathways, such as runoff and drift, dimethoate can reach marine environment, and easily impact common organisms in coastal areas, close to agriculture lands, namely crustaceans. The purpose of this study was to investigate the potential effects of dimethoate exposure (50, 100, and 200 μg/l), for 1 day, on a wide range of markers of oxidative stress and neurotransmission impairment, as well as fatty acids composition and histopathological aspect in the gills of the green crab Carcinus aestuarii. A significant increase in n-3 polyunsaturated fatty acids series, namely the eicosapentaenoic acid (C20: 5n3) and its precursor alpha-linolenic acid (C 18: 3n3) in dimethoate-treated crabs was recorded. Concerning n-6 polyunsaturated fatty acids, we noted a high reduction in arachidonic acid (C20:4n-6) levels. Dimethoate exposure increased the levels of hydrogen peroxide, malondialdehyde, lipid hydroperoxides, protein carbonyl, and caused the advanced oxidation of protein products along with enzymatic and non-enzymatic antioxidant-related markers. Acetylcholinesterase activity was highly inhibited following exposure to dimethoate in a concentration-dependent manner. Finally, deleterious histopathological changes with several abnormalities were noted in exposed animals confirming our biochemical findings. The present study offered unique insights to establish a relationship between redox status and alterations in fatty acid composition, allowing a better understanding of dimethoate-triggered toxicity.

Mead acid production by disruption of Δ12-desaturase gene in Mortierella alpina 1S-4

Mead acid (MA; 20:3ω9) is one of the ω9 series of polyunsaturated fatty acids (PUFAs). MA is used to inhibit the inflammation of joints and is applied to the medicinal or health food field. We aimed to construct MA-producing strains with disruption of the Δ12-desaturase gene (Δ12ds) via an efficient gene-targeting system using the lig4-disrupted strain of Mortierella alpina 1S-4 as the host. The transformants showed a unique fatty acid composition that only comprised ω9-PUFAs and saturated fatty acids, while ω6-and ω3-PUFAs were not detected, and the total composition of ω9-PUFAs, including oleic acid (18:1ω9), 18:2ω9, 20:1ω9, 20:2ω9, and MA, was up to 68.4% of the total fatty acids. The MA production in the Δ12ds-disruptant reached 0.10g/L (8.5%), which exceeded 0.050g/L (4.6%) in the conventional Δ12ds-defective mutant JT-180.

Fisheries and aquaculture by-products modulate growth, body composition, and omega-3 polyunsaturated fatty acid content in black soldier fly (Hermetia illucens) larvae

The black soldier fly (BSF) (Hermetia illucens L.) is one of the most promising species for the production of ingredients, mainly protein, useful for animal feed formulation, owing to its ability to convert organic waste into biomass with a high nutritional value. However, the low percentage of n-3 series polyunsaturated fatty acids (PUFAs) in its fatty acid profile is a limiting factor for the utilization of BSF in fish feed. Recent studies have highlighted that wastes derived from different agro-food value chains could affect the nutritional composition of BSF larvae, depending on the composition of the wastes used as larvae-growing substrate. Due to the significant amount of n-3 PUFA in marine products, both in edible produce and in by-products, in this study, different sources of fish by-products were included in experimental diets for BSF to evaluate the effect of its addition on the final nutritional profile of BSF pre-pupae. One control diet and five experimental diets were prepared to feed the BSF larvae: wheat bran as the control diet (diet B), bycatch from Mediterranean trawl fisheries (diet F), Parapenaeus longirostris processing by-products (diet S), aquaculture processing by-products (diet R), Thunnus albacares processing by-products (diet T), and Engraulis encrasicolus processing by-products (diet A). In this study, the effects of the different diets were analyzed on the growth, body composition, and fatty acid profile of BSF larvae and pre-pupae. The obtained results showed that the different experimental diets affected total lipids content and fatty acids composition, when compared with the control. A significant increase in eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) in BSF larvae and pre-pupae fed with all fish by-products was observed when compared with those fed with diet B, in particular in larvae and pre-pupae fed with diet A, demonstrating that the utilization of fish processing by-products is a suitable solution for improving the nutritional value of insects as ingredients in aqua feeds. The reuse of marine by-products can contribute to the industry’s “zero waste” goal, increasing the sustainability of the fishery value chain and the formulation of new valuable products.

Metabolic analysis of Schizochytrium sp. mutants with high EPA content achieved with ARTP mutagenesis screening.

Eicosapentaenoic acid (EPA) belonged to the ω-3 series of polyunsaturated fatty acids and had physiological functions lipid as regulating blood lipid and preventing cardiovascular diseases. Schizochytrium sp. was considered to be a potential industrial fermentation strain of EPA because of its fast growth, high oil content, and simple fatty acid composition. However, Schizochytrium sp. produced EPA with low production efficiency and a long synthesis path. This research aims to improve the yield of EPA in Schizochytrium sp. by ARTP mutagenesis and to reveal the mechanism of high-yield EPA through transcriptome analysis. ARTP mutagenesis screening yielded the mutant M12 that whereas the productivity of EPA increased 108% reaching 0.48g/L, the total fatty acid concentration was 13.82g/L with an increase of 13.7%. The transcriptomics revealed 2995 differentially expressed genes were identified between M12 and the wild-type strain and transcripts involved in carbohydrate, amino acid, energy, and lipid metabolism were up-regulated. Among them, the hexokinase (HK) and the phosphofructokinase genes (PFK), which can catalyze pyruvate to acetyl-CoA, were increased 2.23-fold and 1.78-fold. Glucose-6-phosphate dehydrogenase (G6PD) and glutamate dehydrogenase (GLDH), which can both generate NADPH, were increased by 1.67-fold and 3.11-fold. Furthermore, in the EPA synthesis module, the expression of 3-oxoacyl-[acyl-carrier protein] reductase(fabG) and carbonyl reductase 4 / 3-oxoacyl-[acyl-carrier protein] reductase beta subunit(CBR4), also up-regulated 1.11-fold and 2.67-fold. These may lead to increases in cell growth. The results provide an important reference for further research on promoting fatty acid and EPA accumulation in Schizochytrium sp.

Deficiency of (n-6) but Not (n-3) Polyunsaturated Fatty Acids Inhibits the Secretagogue Effect of Prolactin in Lactating Rat Mammary Epithelial Cells

The repercussions of various kinds of dietary polyunsaturated fatty acid (PUFA) deficiencies on the fatty acid composition of membranes and on the secretory activity of lactating female rat mammary epithelial cells were investigated. Primiparous female rats were fed different PUFA diets from weaning: adequate (n-6) and (n-3) PUFA supply; overall PUFA deficiency; specific (n-6) PUFA deficiency or specific (n-3) PUFA deficiency. Mammary gland phospholipids contained very low amount of (n-3) PUFA in control rats, and only 1% docosahexaenoic acid. The fatty acid composition of membrane phospholipids reflected the type of diet received by the animals, i.e., the diets deficient in the (n-3) or (n-6) PUFA series resulted in lower (n-3) or (n-6) PUFA, and the (n-3) + (n-6) deficient diet caused a true overall PUFA deficiency in the membranes. The morphology of cells from overall PUFA- or (n-6) PUFA-deficient rats showed an accumulation of secretory vesicles in the cytoplasm. Basal casein secretion was independent of the diet and of the composition of membrane phospholipids. However, prolactin did not have a secretagogue effect on cells from (n-6) PUFA- or overall PUFA-deficient rats but retained this effect on cells from (n-3)-deficient rats. These results emphasize the specific role of (n-6) PUFA in the functioning of the lactating mammary epithelial cell.

Fatty acid metabolic pathway analysis in epididymal adipose and testis in obese mice

It had been proved obesity was one of the main causes of low fertility or infertility in males. In this paper, the fatty acid content of mice epididymal adipose and testis induced by high fat diet was detected by gas chromatography-hydrogen ion flame detector method. Then, the effects of obesity on fatty acid metabolism of mouse epididymal adipose and testis were analyzed by principal component analysis and T-test combined with KEGG pathway. In this way the mechanism of obesity on reproductive system was expounded from the level of fatty acid metabolism. The results were as follows. After feeding the 45% fat diet for 12 weeks, the body weight, BMI, serum TG and CHOL of high fat diet mice were significantly higher than the control group, which meant high fat diet successfully induced obesity and the obese mice developed metabolic abnormalities. Although the weight and the organ coefficient of epididymal adipose and testis in obese mice did not change significantly, principal component analysis showed that there were significant differences in the fatty acid patterns in epididymal adipose of the two groups. Further data mining revealed that the total fatty acids in the epididymal adipose of obese mice decreased significantly. Not only the saturated and monounsaturated fatty acids synthesized by mice their own decreased significantly, but also the n3n6 series polyunsaturated fatty acids caused by exogenous foods or tissue decomposition reduced obviously, while the n6/n3 ratio remained stable. That indicated the epididymal adipose in mice developed fat remodeling with the occurrence of obesity. The C10:0, C12:0 and C16:1n7 contents in testis in obese mice were significantly increased, which might effect the reproductive function of males.

Fatty acid composition of phospholipids and triacylglycerols in the flesh of the thick-lipped grey mullet (Chelon labrosus) living in Tunisian geothermal water and seawater: A comparative study

This study was conducted to elucidate the effects of rearing conditions on the composition of different phospholipid (PLs) classes and triacylglycerols (TAG) of the thick-lipped grey mullet (Chelon labrosus), a muscle originating from seawater and geothermal water. The major fatty acids in the examined lipid classes of the two fish groups were palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1n-9), linoleic acid (C18:2n-6), arachidonic acid (C20:4n-6), eicosapentaenoic acid (C20:5n-3), and docosahexaenoic acid (C22:6n-3). The analyses demonstrated that the fatty acid profiles of the PL classes in the seawater fish group were characterized by the predominance of n-3 polyunsaturated fatty acids (PUFA). By contrast, in geothermal fish, the distribution of PUFA series proportions differed between the phospholipid fractions. It was found PUFA n-3 was particularly abundant in PS and PI, while the n-6 series dominated the PC and PE PUFA group. Nonetheless, it was found that neutral lipid fatty acids were characterized by saturated fatty acids (SFA) followed by monounsaturated fatty acids (MUFA) in the seawater fish and by PUFA in the geothermal fish. The results presented here give useful information on the role of lipid classes in the physiological adaptation of C. labrosus which can serve for the optiminzation of these aquaculture systems.

Slow-Release H2S Donor Anethole Dithiolethione Protects Liver From Lipotoxicity by Improving Fatty Acid Metabolism.

“Lipotoxicity” induced by free fatty acids (FAs) plays a central role in the pathogenesis of many metabolic diseases, with few treatment options available today. Hydrogen sulfide (H2S), a novel gaseous signaling molecule, has been reported to have a variety of pharmacological properties, but its effect on FAs metabolism remains unclear. The purpose of this study was to investigate the effect and mechanisms of anethole dithiolethione (ADT, a sustained-release H2S donor) on hepatic FAs metabolism. ADT was administered daily for 4 weeks in male Syrian golden hamsters fed a high fat diet (HFD), and FAs profiles of liver tissues were analyzed using GC-MS. The results showed that in HFD-fed hamsters, ADT treatment significantly reduced the accumulation of toxic saturated and monounsaturated fatty acids (C16:0, C18:0, C16:1, and C18:1n9), while increased the content of n-6 and n-3 series polyunsaturated fatty acids (C20:3n6, C20:4n6, and C22:6n3). Mechanistically, ADT obviously inhibited the overexpression of acetyl-CoA carboxylase1 (ACC1), fatty acid synthase (FAS), and stearoyl-CoA desaturase1 (SCD1), and up-regulated the levels of fatty acid transport proteins (FATPs), liver fatty acid binding protein (L-FABP), carnitine palmitoyltransferase 1α (CPT1α), fatty acid desaturase (FADS)1 and FADS2. Notably, ADT administration significantly promoted Mitofusin1-mediated mitochondrial fusion and fatty acid β-oxidation. These findings suggest that ADT plays a beneficial role by regulating the synthesis, desaturation, β-oxidation, uptake, binding/isolation, and transport of FAs. In conclusion, ADT is effective in improving FAs metabolic disorders and liver injuries caused by HFD, which renders ADT a candidate drug for lipotoxicity-induced diseases.

Gene Expression and Fatty Acid Profiling in Longissimus thoracis Muscle, Subcutaneous Fat, and Liver of Light Lambs in Response to Concentrate or Alfalfa Grazing.

A better understanding of gene expression and metabolic pathways in response to a feeding system is critical for identifying key physiological processes and genes associated with polyunsaturated fatty acid (PUFA) content in lamb meat. The main objective of this study was to investigate transcriptional changes in L. thoracis (LT) muscle, liver, and subcutaneous fat (SF) of lambs that grazed alfalfa (ALF) and concentrate-fed (CON) slaughtered at 23 kg and using the Affymetrix Ovine Gene 1.1 ST whole-genome array. The study also evaluated the relationship between meat traits in LT muscle, including color, pigments and lipid oxidation during 7 days of display, α-tocopherol content, intramuscular fat (IMF) content and the fatty acid (FA) profile. Lambs that grazed on alfalfa had a greater α-tocopherol concentration in plasma than CON lambs (P < 0.05). The treatment did not affect the IMF content, meat color or pigments (P > 0.05). Grazing increased the α-tocopherol content (P < 0.001) and decreased lipid oxidation on day 7 of display (P < 0.05) in LT muscle. The ALF group contained a greater amount of conjugated linoleic acid (CLA), C18:3 n−3, C20:5 n−3, C22:5 n−3, and C22:6 n−3 than did the CON group (P < 0.05). We identified 41, 96 and four genes differentially expressed in LT muscle, liver, and subcutaneous fat, respectively. The most enriched biological processes in LT muscle were skeletal muscle tissue development, being the genes related to catabolic and lipid processes downregulated, except for CPT1B, which was upregulated in the ALF lambs. Animals grazing alfalfa had lower expression of desaturase enzymes in the liver (FADS1 and FADS2), which regulate unsaturation of fatty acids and are directly involved in the metabolism of n−3 PUFA series. The results found in the current study showed that ingesting diets richer in n−3 PUFA might have negative effects on the de novo synthesis of n−3 PUFA by downregulating the FADS1 and FADS2 expression. However, feeding diets poorer in n−3 PUFA can promote fatty acid desaturation, which makes these two genes attractive candidates for altering the content of PUFAs in meat.

Effect of silver nanoparticles on gill membranes of common carp: Modification of fatty acid profile, lipid peroxidation and membrane fluidity

Although the toxicity of silver nanoparticles (AgNPs) in aquatic organisms has been extensively investigated, the mechanism by which AgNPs damage membranes remains unclear. This study investigated the toxic effects of a series of sub-lethal concentrations of AgNPs on the membranes of freshwater carp (Cyprinus carpio) gills, based on changes in membrane fatty acid (FA) profile, membrane fluidity, membrane lipid peroxidation, and histopathology. Most of the FAs in fish gill membrane was not significantly affected by exposure to multiple AgNPs concentrations, only few significant changes occurred in some specific FAs species at a high concentration of AgNPs exposure. In particular, high concentrations of AgNPs significantly decreased the proportions of two important long-chain n-3 series polyunsaturated FAs (C20: 5n3, and C22: 6n3), resulting in a decreased ratio of n-3 polyunsaturated FAs to n-6 polyunsaturated FAs (Σn-3UFA/Σn-6UFA). The AgNPs also caused a dose-dependent decrease in fish gill membrane fluidity, increased the level of lipid peroxidation, and inhibited Na+/K+-ATPase enzyme activity. Further histopathological examination revealed that exposure to AgNPs can cause toxic responses in the lamellae, including the thinning of the basement membrane, malformation, and inflammation. Together, the results suggest that the mechanism of AgNPs membrane toxicity involves the oxidization of long-chain omega-3 unsaturated FAs to saturated FAs via lipid peroxidation, resulting in, decreased membrane fluidity and ultimately the destruction of the normal physiological function of the fish gill membrane. The findings contribute significantly to our understanding of nanoparticle-induced membrane toxicity and potential risks in aquatic environments.

Effects of a diet enriched with eicosapentaenoic, docosahexaenoic and glutamine on cytokines as immunological markers for systemic inflammation in bitches before and after ovariohysterectomy.

The post-operative period can generate immunological stress and can be modulated through supplementation with the omega-3 series of polyunsaturated fatty acids. This study aimed to evaluate the effects of diets enriched with high doses of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids and glutamine on inflammatory mediators in dogs before and after ovariohysterectomy (OVH). Twelve female dogs were divided into two groups: group A was fed a commercial diet without the addition of EPA and DHA, and group B was fed an experimental diet enriched with EPA and DHA (0.2g/100kcal). Experimental diet intake initiated 21days before surgery and continued until 30days after OVH. Parameters measured were serum cytokines (TNF-α, IL-6 and IL-10), C-reactive protein (CRP), IGF-1, lymphoproliferation and body composition before and after surgery. Statistical analyses were performed with SAS software considering the effects of age and diet and their interactions, and means were compared by the Tukey test. There was no difference between groups in body weight (p=.682), lean mass (p=.101) and body fat (p=.103). There were no group differences in serum concentrations of TNF-α, IL-6, IL-10, IGF-1, CRP and the percentage of lymphocyte proliferation. However, a time effect for TNF-α was observed (p<.001), in which T0P (10days after the surgical procedure) presented lower values of this cytokine when compared to the other evaluation time points; and interaction effects between group and time were observed for serum concentrations of IL-6 (p<.001) and IL-10 (p=.002). OVH procedure was not considered invasive enough to increase inflammatory cytokines after 30 days of surgery, as well as the dosage of the EPA and DHA used before and after the surgery did not modulate the inflammatory markers.

Is fatty acid composition of human bone marrow significant to bone health?

The bone marrow adipose tissue (BMAT) is a conserved component of the marrow microenvironment, providing storage and release of energy and stabilizing the marrow extent. Also, it is recognized both the amount and quality of BMAT are relevant to preserve the functional relationships between BMAT, bone, and blood cell production. In this article we ponder the information supporting the tenet that the quality of BMAT is relevant to bone health. In the human adult the distribution of BMAT is heterogeneous over the entire skeleton, and both BMAT accumulation and bone loss come about with aging in healthy populations. But some pathological conditions which increase BMAT formation lead to bone impairment and fragility. Analysis in vivo of the relative content of saturated and unsaturated fatty acids (FA) in BMAT indicates site-related bone marrow fat composition and an association between increased unsaturation index (UI) and bone health. With aging some impairment ensues in the regulation of bone marrow cells and systemic signals leading to local chronic inflammation. Most of the bone loss diseases which evolve altered BMAT composition have as common factors aging and/or chronic inflammation. Both saturated and unsaturated FAs originate lipid species which are active mediators in the inflammation process. Increased free saturated FAs may lead to lipotoxicity of bone marrow cells. The pro-inflammatory, anti-inflammatory or resolving actions of compounds derived from long chain poly unsaturated FAs (PUFA) on bone cells is varied, and depending on the metabolism of the parent n:3 or n:6 PUFAs series. Taking together the evidence substantiate that marrow adipocyte function is fundamental for an efficient link between systemic and marrow fatty acids to accomplish specific energy or regulatory needs of skeletal and marrow cells. Further, they reveal marrow requirements of PUFAs.

Expression of Vitreoscilla hemoglobin enhances production of arachidonic acid and lipids in Mortierella alpina

BackgroundArachidonic acid (ARA, C20:4, n-6), which belongs to the omega-6 series of polyunsaturated fatty acids and has a variety of biological activities, is commercially produced in Mortierella alpina. Dissolved oxygen or oxygen utilization efficiency is a critical factor for Mortierella alpina growth and arachidonic acid production in large-scale fermentation. Overexpression of the Vitreoscilla hemoglobin gene is thought to significantly increase the oxygen utilization efficiency of the cells.ResultsAn optimized Vitreoscilla hemoglobin (VHb) gene was introduced into Mortierella alpina via Agrobacterium tumefaciens-mediated transformation. Compared with the parent strain, the VHb-expressing strain, termed VHb-20, grew faster under both limiting and non-limiting oxygen conditions and exhibited dramatic changes in cell morphology. Furthermore, VHb-20 produced 4- and 8-fold higher total lipid and ARA yields than those of the wild-type strain under a microaerobic environment. Furthermore, ARA production of VHb-20 was also 1.6-fold higher than that of the wild type under normal conditions. The results demonstrated that DO utilization was significantly increased by expressing the VHb gene in Mortierella alpina.ConclusionsThe expression of VHb enhances ARA and lipid production under both lower and normal dissolved oxygen conditions. This study provides a novel strategy and an engineered strain for the cost-efficient production of ARA.

A Novel ω3-Desaturase in the Deep Sea Giant Tubeworm Riftia pachyptila

One paradox of the trophic biochemistry of the deep sea giant tubeworm Riftia pachyptila, endemic to hydrothermal vent sites and nourished by polyunsaturated fatty acid (PUFA) deficiency chemolitoautotrophic sulfide-oxidizing bacteria, is the source of their PUFAs. Biosynthesis of PUFA starts with two precursors C18:2n-6 and C18:3n-3, which cannot be biosynthesized by most animals due to lack of ω6- and ω3-desaturase; thus, C18:2n-6 and C18:3n-3 are generally essential fatty acids for animals. Here, we characterized a gene derived from the R. pachyptila located by hydrothermal vent, which encoded a novel ω3-desaturase (Rp3Fad). The gene was identified by searching the R. pachyptila transcriptome database using known ω3-desaturases, and its predicted protein showed 37-45% identical to ω3-desaturases of fungus and microalgae, and only 31% identitical to nematode Caenorhabditis elegans ω3-desaturase. Expression in yeast Saccharomyces cerevisiae showed that the Rp3Fad could desaturate C18:2n-6 and C18:3n-6 into C18:3n-3 and C18:4n-3, respectively, displaying a Δ15 activity similar to plant ω3-desaturase, but it showed no activity towards C20 n-6 PUFA substrates, differing from the well-characterized C. elegans ω3-desaturases. Δ5, Δ6, Δ8, and Δ12 activity were also tested, resulting in no corresponding production. The function of ω3-desaturase identified in R. pachyptila could produce C18:3n-3 used in synthesis of n-3 series PUFAs, suggesting an adaption to PUFA deficiency environment in deep sea hydrothermal vent.

Comparison of nutritional and antinutritional traits among different species (Lupinus albus L., Lupinus luteus L., Lupinus angustifolius L.) and varieties of lupin seeds.

In order to promote the use of lupin in pig nutrition, in this research the nutritional characteristics (i.e. dietary fibre, alkaloid and fatty acid profile) and the invitro gas production of 12 lupin varieties grown in the Mediterranean basin and belonging to three lupin species (Lupinus albus, Lupinus angustifolius and Lupinus luteus) were assessed. Four varieties of L.albus (Asfer, Lublanc, Lutteur and Multitalia) were grown in South Campania. Three varieties of L.luteus (Dukat, Mister and Taper), three of L.angustifolius (Jindalee, Sonet and Wonga) and two of L.albus (Rosetta and Luxor) were grown in Eastern Sicily. Lupinus albus varieties showed interesting nutritional and dietetic characteristics (i.e. high protein and low fibre content); the lipid fraction, rather elevated, is well represented by monounsaturated fatty acids (544g/kg), whereas saturated fatty acids (SFAs) are less represented (167g/kg) and the n-3/n-6 ratio (0.510) is the most favourable. Lupinus luteus varieties presented the most remarkable dietetic aspects, in terms of polyunsaturated fatty acid (PUFA) content (569g/kg), n-6 PUFA series (490g/kg), UFA/SFA (5.24) and PUFA/SFA (3.56) ratios and atherogenic (0.059) and thrombogenic (0.100) indices and very low alkaloid content (1.07mg per 100g). Lupinus angustifolius varieties showed the least interesting nutritional and dietetic characteristics: low protein and fat content, high fibre level, high SFA amount (248g/kg) and the lowest favourable nutritional indices (IA: 0.164 and IT: 0.334). Regarding the fermentation process, in L. albus, the tendency to increase the rate of gas production during the early stages of fermentation suggests that the high presence of alkaloids did not affect the invitro degradability, production of short-chain fatty acids and fermentation process, probably due to their concentration and/or water solubility. Lupinus angustifolius and L.luteus showed intermediate and slightly worse invitro fermentation patterns respectively. From a nutritional and dietetic point of view, lupin may represent an interesting alternative to soya bean in pig feeding.

Antarctic red macroalgae: a source of polyunsaturated fatty acids

The n-3 and n-6 series of polyunsaturated fatty acids (PUFAs) are important for numerous metabolic functions that reduce the risk of inflammation, cancer, and heart diseases. These fatty acids (FAs) have been detected in high concentrations in some species of algae. The amount of the n-3 and n-6 PUFAs is closely associated with abiotic factors, such as solar radiation intensity, salinity, and temperature variation. However, abiotic influence on PUFA levels, along with the physiological function of these molecules in algae, remains inconclusive. In the present study, the quantities of the n-3 and n-6 in Antarctic red algae species Iridaea cordata, Palmaria decipiens, Plocamium cartilagineum, and Pyropia endiviifolia were determined. The lipids were extracted from the macroalgae according to the method followed by Bligh and Dyer (1959) and converted to methyl esters for further analysis using gas chromatography. The main n-6 PUFA identified and quantified in this study of Antarctic red algae were linoleic acid (18:2n-6), dihomo-γ-linolenic acid (20:3n-6), and arachidonic acid (20:4n-6). The eicosapentaenoic acid was detected at high concentrations in all species, with approximately 62.8% of total FA in P. endiviifolia, 75.4% in P. decipiens, 50.4% in I. cordata, and 20.1% in P. cartilagineum. The results corroborate those of the literature and show that PUFAs increased in red algae environments, with increased production of n-3 and n-6 PUFAs.

Study on Nutritional Value of Instant Sea Cucumber Processed by the New Processing Approach

In this study, the micrograph, the composition of amino acids and fatty acids were analyzed contrastively among the fresh, instant and commercial sea cucumber. The micrographs of fresh, instant and commercial sea cucumbers indicated that the processing technology of instant sea cucumber could effectively inhibit the damage of sea cucumber collagen structure and better maintain its original structure. Depending on the FAO/WHO and whole egg model to evaluate the sea cucumber protein's nutritional value, the results showed that instant sea cucumber owned the higher content of amino acid and the perfect profiles of amino acid, which meant that the protein of instant sea cucumber was easily digested and absorbed by human body and belonged to high quality protein. The instant sea cucumber was rich in essential fatty acids and n-3 series of polyunsaturated fatty acids and suitable for the Chinese residents' consumption. This study suggested that the instant sea cucumber was superior to the commercial sea cucumber with effective inhibition of the losing of nutrients and was fit for Chinese residents' consumption as a kind of high-quality products.

Interactive effects of dietary composition and hormonal treatment on reproductive development of cultured female European eel, Anguilla anguilla

Farmed female eels were fed two experimental diets with similar proximate composition but different n-3 polyunsaturated fatty acid (PUFA) levels. Both diets had similar levels of arachidonic acid (ARA), while levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in one diet were approximately 4.5 and 2.6 times higher compared to the other diet, respectively. After the feeding period, each diet group was divided into two and each half received one of two hormonal treatments using salmon pituitary extract (SPE) for 13 weeks: i) a constant hormone dose of 18.75mg SPE/kg initial body weight (BW) and ii) a variable hormone dosage that increased from 12.5mg SPE/kg initial BW to 25mg SPE/kg initial BW. Results showed a significant interaction between diets and hormonal treatments on gonadosomatic index (GSI), indicating that the effect of broodstock diets on ovarian development depends on both nutritional status and hormonal regime. Females fed with higher levels of n-3 series PUFAs and stimulated with the constant hormonal treatment reached higher GSIs than those receiving the variable hormonal treatment. However, when females were fed lower levels of n-3 series PUFAs there was no difference in the effect of hormonal treatments on GSI. We also found that, independent of hormonal treatment, the diet with higher levels of n-3 series PUFAs led to the most advanced stages of oocyte development, such as germinal vesicle migration. Concentration of sex steroids (E2, T, and 11-KT) in the plasma did not differ between diets and hormonal treatments, but was significantly correlated with ovarian developmental stage. In conclusion, increasing dietary levels of n-3 PUFAs seemed to promote oocyte growth, leading to a more rapid progression of ovarian development in European eel subjected to hormonal treatment.

The Effect of Lupine Seed in Broiler Diet on Animal Performance and Fatty Acids Profile of their Meat

Abstract Alkaloid-free lupine seed may represent an alternative for ensuring the vegetable protein in poultry feed. Given the weight but especially the place and role of fats in maintaining consumer health, in our research we watched the effect of alkaloid free lupine seed in the diet of broiler (chicken and turkey), the animal performance and especially the effect on the fatty acids composition in the chest intramuscular fat. The experiment was conducted as a completely randomized experimental design consisting of two treatments involving a control diet consisting of corn - soybean grits (LC) and an experimental diet (LE) in which the proteins from soy grits were replaced by alkaloid free lupine flour. Two groups were organized: LC (control) – in whose diet soybean meal was used and LE protein (experimental) - in whose diet alkaloid free lupine seeds were used. In the chicken broiler diet, the protein derived from soybean meal was replaced with alkaloid free lupine flour in proportion of 30% during days 1-21 and 60% during days 22-42 (14.0-25.7% lupine ratio in the combined fodder structure). As for the turkey broiler, lupine seed accounted for 30% of combined fodder structure, substituting between 40% (breeding stage 0-3 weeks) and 75% (breeding stage 15-18 weeks) of protein provided by soybean meal. Substitution of soybean meal protein in the broiler diet by introducing alkaloid free white lupine beans in broiled food has no negative effect on their bio-performance. Supplementing the broilers diet with lupine flour resulted in a decreased share of saturated fatty acids with high atherogenic potential (C14:0, C16:0, C18:0) in breast intramuscular fat and increased the share of n-3 series polyunsaturated fatty acids (I±-linolenic acid especially), which at their turn decreased the n-3/n-6 series fatty acids in breast, thus increasing the nutritional quality of poultry meat, analysed in terms of impact on human consumer health.  Keywords : alkaloid-free lupine, fatty acids composition, meat, broiler. Â

Additive effect of linseed oil supplementation on the lipid profiles of older adults.

BackgroundLinseed oil has been investigated as a rich source of n-3 series polyunsaturated fatty acids, which mainly produce a non-atherogenic lipid profile. The objective of this study was to investigate the effect of linseed oil supplementation associated with nutritional guidelines on the lipid profiles of older adults, according to the intake of saturated fatty acids (SFA).MethodsWe conducted a double-blind, placebo-controlled clinical trial with 110 older adults randomized in two groups: placebo and linseed oil. The linseed oil group received supplementation with 3 g of linseed oil. Both groups received nutritional guidance and were supplemented for 90 days with monthly blood collection for biochemical analysis. The dietary intake of saturated fat was subdivided into low (<7% SFA/day of the total energy value) and high consumption groups (>7% SFA/day of the total energy value).ResultsLow SFA (<7% SFA/day of total energy value) consumption was associated with lower total cholesterol concentrations. However, we observed that the linseed oil group, including older adults who consumed >7% SFA/day, had a greater reduction in total cholesterol than the placebo group (P=0.020). The same was observed for low-density lipoprotein (LDL) cholesterol (P<0.050), suggesting an additive effect of linseed oil and diet. High-density lipoprotein (HDL) cholesterol concentrations were increased significantly in only the linseed group, suggesting that the nutritional intervention alone did not improve HDL cholesterol.ConclusionThe results suggest that the nutritional intervention was effective, but linseed oil showed notable effects by increasing the HDL cholesterol concentration. In addition, consumption of <7% SFA/day of the total energy value increased the effect of linseed oil, demonstrating the importance of reducing the consumption of saturated fat.